What is the difference between UUID v4 and UUID v7?

UUID v4 is purely random, which can fragment B-tree database indexes at high scale. UUID v7 embeds a millisecond Unix timestamp prefix so new records sort chronologically while staying globally unique.

Are generated UUIDs cryptographically secure?

Yes. ToolCix uses `crypto.randomUUID()` and `crypto.getRandomValues()` rather than weak `Math.random()`.

Can I remove hyphens for compact tokens?

Yes—uncheck Include Hyphens to output 32-character hex strings.

Does ToolCix store or track generated UUIDs?

Never—all identifiers are generated strictly inside your browser session.

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UUID Generator (v4 & v7)

Built for database architects, API developers, and QA testers creating unique primary keys, test fixtures, and correlation IDs.

UUID Standard

Batch Size (1–100)

Include HyphensUPPERCASE

Generated Identifiers

c257ac7a-e6a0-48f5-99b8-3bed43c041e1
fe1f16e1-8a0e-408f-aa7f-7937ed6175f9
8a6be65d-5a63-4c60-9da5-82595a4cac8b
2267d2ac-4dbd-4d4e-a661-aed3884aaec8
ba31c921-7193-45b3-bc40-29e77d22fded

How to Use UUID Generator (v4 & v7)

1Choose UUID Version 4 (cryptographic random) or Version 7 (Unix-ms time-ordered).
2Select batch quantity (1 to 100) and formatting options (lowercase, uppercase, or no hyphens).
3Click Generate UUIDs using `crypto.getRandomValues`.
4Copy individual IDs or download the entire batch as plain text or JSON.

Key Features

Supports both classic UUID v4 and modern sortable UUID v7 (RFC 9562)
Cryptographically secure randomness via `window.crypto`
Batch generation (1–100) with JSON array or newline export
Uppercase and compact hyphen-free toggles

Why Modern Databases Prefer Time-Ordered UUID v7

Classic UUID v4 identifiers are wonderful for distributed uniqueness, yet random primary keys force databases like PostgreSQL and MySQL to jump across random index pages on every insert. RFC 9562 standardized UUID v7 specifically to solve this: the first 48 bits encode a monotonic millisecond timestamp while the remaining bits provide cryptographic entropy.

ToolCix lets engineers switch seamlessly between v4 and v7, customize casing and hyphens, and export ready-to-seed JSON arrays for test suites.

Collision Probability in Practice

With 122 random bits in UUID v4 (and 74+ random bits per millisecond in UUID v7), the odds of a random collision across billions of rows are astronomically negligible.